Clinical improvement in ankylosing spondylitis with rifamycin SV infiltrations of peripheral joints.

In an open study, a new treatment modality was evaluated in 22 patients with active ankylosing spondylitis and compared with oral treatment. Patients were given a 10-week course of rifamycin SV infiltrations to all large peripheral joints, whether or not affected, and were followed for up to 12 months after the end of treatment. Clinical improvements observed at the end of the 10-week treatment cycle persisted for 12 months: morning stiffness (P less than 0.02); subjective pain (P less than 0.0001); Schober's test (P less than 0.006); hand-ground distance (P less than 0.001); erythrocyte sedimentation rate (P less than 0.001); and C-reactive protein (P less than 0.04). The number of painful joints became significantly lower at 6 (P less than 0.01) and 12 months (P less than 0.02) of the follow-up period. Oral administration of rifampin at three times the intra-articular dosage was devoid of any therapeutic activity. It is not known how treatment of peripheral joints influenced the inflammatory process at the level of the axial skeleton. These results must be considered preliminary due to the small number of patients and the short follow-up period, and because it was an open study.